Superhydrophobic silicone-coating on carbon foam for efficient oil adsorption

• Published in: Materials letters 2022-03, Vol.311, p.131525, Article 131525
• Main Authors: Bagal, Rohit, Chouhan, Devesh Kumar, Sahoo, Bichitra Nanda, Chaudhari, Rahul, Bhongale, Chetan J., Patro, T. Umasankar
• Format: Article
• Language: English
• Subjects: Adsorption; Carbon; Carbon materials; Coating; Contact angle; Hydrophobic surfaces; Hydrophobicity; Materials science; Polydimethylsiloxane; Polymers; Polyurethane foam; Porous materials; Silicone resins; Silicones; Solvents; Temperature dependence; Vapor deposition
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2021.131525

[Display omitted] •Silicone oil was coated on carbon foam to produce superhydrophobic material.•Water contact angle of the coated foam was found to be ∼ 173°.•The coated foam efficiently adsorbs oil and separates oil from oil-water emulsion.•The water flux was found to be ∼ 7.3 × 105 L m−3h−1 with efficiency of ∼ 98%. Herein, a one-step solvent-free hydrophobic coating using vapour deposition of poly(dimethyl siloxane) (PDMS) oil on carbon foam, prepared by carbonization of flexible polyurethane foam is reported. The silicone-coating was found to be uniform on the foam surface and the coated foam exhibited superhydrophobic behaviour with a striking water contact angle (WCA) reaching up to ∼ 173°, when the coating was performed at 320 °C for 14 h, from ∼ 106° for uncoated foam. The hydrophobicity showed dependency on the coating temperature and time. The coated foam efficiently adsorbed solvent/oil from oil-water mixture in batch experiments and separated water from oil-water emulsion continuously with a flux of ∼ 7.3 × 105 L m−3h−1 gravitationally with an efficiency of ∼ 98%. The coated CF showed excellent repeatability of oil adsorption and could even adsorb oil in harsh environments.